the varation leads scientists to conclude more about the Earth's composition Plate Movement Earthquakes: Guatemalan Earthquake (1976) the main railroad line between Puerto Barrios and Guatemala City shifted location San Francisco Earthquake (1906) the ground of San Francisco shook as the San Andres Fault moved the plate boundaries of the North American Plate and the Pacific Plate the result of a sudden release of energy in the Earth's crust Volcanoes: any place in the Earth's crust where mantle material and other substance reach the surface Java: Chain of Volcanoes along the coastline of Java, lies the plate boundary of the Eurasian Plate and and the Australian Plate

the boundary is convergant subduction zone, forming a chain of volcanoes along the island of Java Mid-Ocean Ridge along the many plate boundaries in the middle of the Atlantic Ocean lies a divergent boundary

at a divergent boundary the plates are pulling apart, filling the gap is molten mantle (lava), forming a chain of volcanoes Pangea the "super continent" that was once composed of all of the continents, 200 million years ago Evidence Coal Coal Rock Strata Rock Strata Rock Strata Fossils Fossils Fossils coal is only formed in tropical climatescoal was found in America and Europe rock sequence (layer) were very similar, if not the same, in different regions of the world Lystrosaurus fossils were found in Africa, Antartica, and Indiathose regions have very different climates in modern times pushed apart by the spreading of the Atlantic Ocean and the Mid-Ocean Ridge Convection the rock material of the asthenosphere is heated by the core the heated molecules start to move fastert, getting further apart, and less dense than the material above it Mount Kilimanjaro Shield Volcano gentle sloping sides result of low silica content, creating fluid lava non-explosive gentle sloping sides, non-explosive, result of plates moving apart plates spreading apart/getting thinner located in the Great African Rift Valley the African Plate is pulled apart, getting thinnerthe movement is forming a Rift Valley along the southwestern stretch of Africaalong the Rift valley is Mount Kilimanjaro (a volcano), a result of the Rift Zonethe Rift Zone is a result of the Divergant Boundary the Valley if splitting to be African Plate: Divergant Boundary two plates pull apart/the splitting of a plate http://www.youtube.com/watch?v=_I7DPl65BLM http://www.youtube.com/watch?v=oMUTDe6LR4o&NR=1 http://www.youtube.com/watch?v=UHcse1jJAto Triangulation Location of Plate Boundaries triangulation by using the seismic wave timing of three (or more) locations around the world, scientists can locate the epicenter of an earthquake connecting the dots by connecting the locations of epicenters, scientists can locate plate boundaries the interaction between plate boundaries form volcanoes the material in the mantle begins to rise/float (about 2" per year) once the material rises to the crust, it begins to spread as the material spreads, it becomes more exposed to a cooler atmostphere, and begins to cool (lose energy) the cooled molecules start to move slower, getting closer together and more dense than the material below it the cooled molecules start to move slower, getting closer together and more dense than the material below it the more dense material begins to sink the more dense material begins to sink the process repeates itself the process repeates itself the force pushes on the crust, causing the movement of the plates the movement in the Asthenosphere pushes on the crust, causing the movement of the plates http://www.youtube.com/watch?v=uGcDed4xVD4&feature=related